Fix scanf return value

Hello,

The return value of sscanf() is wrong for non-matching %[..] formats, because
n is always increased even if no characters match. Example:

ret = sscanf(buf, " %15[^#= \t\n] = %255[^\n]\n", cmd, str);

would return 1 for bug="#", while it should be 0. With the below patch this
case works.

Greetings,

Indan


Index: lib/__v_scanf.c
=================================================================== RCS file:
/cvs/dietlibc/lib/__v_scanf.c,v
retrieving revision 1.21
diff -u -p -b -B -w -r1.21 __v_scanf.c
--- lib/__v_scanf.c	7 Jul 2008 12:52:55 -0000	1.21
+++ lib/__v_scanf.c	4 Nov 2010 22:17:32 -0000
@@ -338,6 +338,7 @@ exp_out:
 	    char cset[256];
 	    int flag_not=0;
 	    int flag_dash=0;
+	    int i;
 	    memset(cset,0,sizeof(cset));
 	    ch=*format++;
 	    /* first char specials */
@@ -370,15 +371,15 @@ exp_out:
 	    /* like %c or %s */
 	    if (!flag_discard) {
 	      s=(char *)va_arg(arg_ptr,char*);
-	      ++n;
 	    }
-	    while (width && (tpch>=0) && (cset[tpch]^flag_not)) {
-	      if (!flag_discard) *s=tpch;
-	      if (tpch) ++s; else break;
-	      --width;
+	    for (i=0; i<width && tpch>=0 && (cset[tpch]^flag_not); ++i){ +	      if
(!flag_discard) s[i]=tpch;
 	      tpch=A_GETC(fn);
 	    }
-	    if (!flag_discard) *s=0;
+	    if (!flag_discard && i) {
+	      s[i] = 0;
+	      ++n;
+	    }
 	    ++format;
 	  }
 	  break;